Organizations such as on-line retailers, Internet service providers, search providers, financial institutions, universities, and other computing-intensive organizations often conduct computer operations from large scale computing facilities. Such computing facilities house and accommodate a large amount of server, network, and computer equipment to process, store, and exchange data as needed to carry out an organization's operations. Typically, a computer room of a computing facility includes many server racks. Each server rack, in turn, includes many servers and associated computer equipment. Some server systems include servers of different sizes. For example, a standard 19-inch rack may hold 10 to 20 servers having various heights of 1U, 2U, and 3U (a rack unit “U” is 1.75 inches).
In typical industry-standard racks, slots are in fixed locations. Moving a server generally requires the time-consuming and potential service interruption of powering off the server, at least partially uncabling the server, physically removing the server from the rack, then physically adding the host back to the rack in a new location.
One challenge encountered in server system utilization is increasingly fragmented available physical space over time. For example, a rack may have a filled 1U space with adjacent empty 1U spaces on either side and no other space available. To then add a new 2U server to this rack may require moving the 1U server to create a contiguous 2U empty slot.
When an individual server fails or falls below an acceptable level of performance, the server may be removed from the rack. In rack systems that include more than one server size, however, a replacement server may not fit in the slot or slots created by removal of the old server(s). For example, in a conventional rack for which a single 3U server is to replace three 1U servers scattered over the height of the rack, none of the individual slots created by removal of the three 1U servers will accommodate the new 3U server. The 3U server may be placed in an open larger slot, but this will result in wasted rack space in the form of the unfilled 1U slots. Alternatively, various servers that are not being replaced might be temporarily extracted from the rack and the servers rearranged to create a 3U slot. Such rearrangements are likely to be time-intensive and labor-intensive to carry out, however.
In some systems, a rack-level power distribution unit (“PDU”) is provided in a rack to distribute electrical power to the many servers in the rack. The rack-level PDU may include a large number of receptacles, each of which may be used to supply power to a different server by way of a power cable. Over time, management of the power cables for the numerous servers during maintenance in the rack may become cumbersome and time-consuming. For example, if a server needs to be moved from one location in a rack to another, the power cable between the server and the PDU receptacle may not be long enough to allow the server to remain plugged in while the server is moved to the new location. As such, the power cable for the server may need to be unplugged to allow the move, which results in a temporary loss of computing capacity and additional maintenance procedures (such as powering up and rebooting the server after it has been reinstalled in the new location). Moreover, the power cables for the various servers may become entangled or block air flow through the rack.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to.